Malicious RTF / .DOC — malware analysis report

Static analysis result for SHA-256 f1b005524d6c469f…

MALICIOUS

RTF / .DOC

14.2 KB First seen: 2022-08-22
MD5: 2719979da7e35b2cd8c9cda699c533b2 SHA-1: 3e1d013cc7e59f89db0e446d6c47cdb4d686b79f SHA-256: f1b005524d6c469f7a4cee8bc71cf3bd5660b34f301a4276a222ccdae540063f
140 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment T1204.002 Malicious File T1059.005 Visual Basic

The sample is an RTF document containing OLE object data, specifically triggering the CVE-2017-11882 Equation Editor vulnerability. The document body contains a lure instructing the user to 'enable editing', a common tactic to bypass macro security. The embedded OLE object is likely designed to execute a second-stage payload upon activation.

Heuristics 4

  • CVE-2017-11882 — Equation Editor FONT record overflow critical CVE likely CVE_2017_11882
    Equation Editor MTEF contains an overlong FONT typeface field, the vulnerable copy primitive for CVE-2017-11882. This is stronger evidence than the Equation Editor CLSID alone because it identifies the malformed record that drives code execution in EQNEDT32.EXE.
  • \objupdate forces OLE activation high RTF_OBJUPDATE
    RTF contains \objupdate — forces automatic OLE object instantiation when the document is opened, bypassing user interaction. Almost exclusively seen in Equation Editor exploit documents.
  • OLE object data medium RTF_OBJDATA
    RTF contains 2 \objdata section(s) — embedded OLE objects
  • Macro/content-enable lure medium SE_ENABLE_LURE
    Document instructs the user to enable macros or editing — a common technique used by malware droppers to bypass Office macro security settings

Extracted artifacts 1

Files carved from inside the sample during analysis.

FilenameKindSourceSize
objdata_00_off00000a43.bin
78b0b5746f7cb09fad060267e0df2dea157a5d142a5d4953598e15245bb6144f
rtf-objdata-decoded RTF \objdata at offset 0xA43 3776 bytes